Thread feeding device for textile machines

ABSTRACT

A thread feeding device for textile machines comprising a rotary driving cylinder and an endless belt which, in normal operation, is applied along an arc of a circle against the cylinder to engage and advance thread passing between the belt and the cylinder wherein the belt is mounted on two idler rollers attached to a pivotable supporting arm, characterized in that the supporting arm is combined with means for positioning and pretensioning the belt in an intermediate position between an idle and a working position in which position the belt is in contact with the driving cylinder over an embraced arc and at a pressure much less than that necessary to advance the thread during normal operation. The invention is particularly adapted for use in texturizing machines, and especially, for those texturizing by false twist.

United States Patent [191 Venot [451 Aug. 27, 1974 1 THREAD FEEDING DEVICE FOR TEXTILE MACHINES [75] Inventor: Jean Venot, Villerest, France [73] Assignee: Chavanoz S.A., Chavanoz, France [22] Filed: June 18, 1973 [21] Appl. No.: 370,725

[31)] Foreign Application Priority Data June 26, 1972 France 72.23274 [52] US. Cl. 226/171 [51] Int. Cl B65h 17/34 [58] Field 01" Search 226/170, 171, 195

[56] References Cited FDREIGN PATENTS OR APPLICATIONS 1,149,841 7/1957 France 226/171 1,195,159 5/1959 France 226/171 547,079 10/1955 Italy 171/ 575,314 7/1955 Canada 226/171 Primary Examiner-M. Henson Wood, .lr. Assistant Examiner-Gene A. Church Attorney, Agent, or Firm--Luke l. Wilbum, In; H. William Petry ABSTRACT A thread feeding device for textile machines comprising a rotary driving cylinder and an endless belt which,

in normal operation, is applied along an arc of a circle against the cylinder to engage and advance thread passing between the belt and the cylinder wherein the belt is mounted on two idler rollers attached to a pivotable supporting arm, characterized in that the supporting arm is combined with means for positioning and pretensioning the belt in an intermediate position between an idle and a working position in which position the belt is in contact with the driving cylinder over an embraced arc and at a pressure much less than that necessary to advance the thread during normal operation.

The invention is particularly adapted for use in texturizing machines, and especially, for those texturizing by false twist.

11 Claims, 5 Drawing Figures Pmmanwczmu 3.831 330 SIEEI 2 W 5 PAIENTEB E 3.831. 830

sum 3 or 5 PATENIED mezmn SHEH U 5 PAIENIEDmczmu sum sw 5 THREAD FEEDING DEVICE FOR TEXTILE MACHINES The present invention relates to a new thread feeder designed for textile machines and more particularly for texturizing machines, particularly for false twist machines.

Theinvention relates more particularly to a device of the type comprising, essentially, a rotary cylinder and an endless belt applied along an arc of a circle against the cylinder, the linear speedsof these elements being equal to those sought for the thread, such an arrangement is described in particular in French Pat. No. 1,149,841. In feeders of this type, the endless belt is mounted on two rollers with parallel axes between which the cylinder is placed. The driving element is preferably constituted by the cylinder which is driven in rotation. The belt in contact with the cylinder is mounted on two idler rollers carried on two support shafts parallel to the cylinder. These shafts rest on an oscillating support subject to the action of a spring which tends to place the belt against the driving cylinder.

The entrainment capacity of the thread by the feeder is obtained either by adjusting the pressure of the belt on the cylinder, or by combining these two factors. By entrainment capacity, we mean the force with which the feeder is able to advance or deliver the thread. In every case, this entrainment capacity must be adjusted in such a way that it will be greater than the breaking limit of the thread it delivers. In this way, in case of variation in the conditions of treatment, and primarily when the tension of the thread increases above the feeder, the latter will cause the thread to break.

The devices of this type embodied heretofore can assume only two positions, namely, either (1) idle, the belt not touching or being in contact with the cylinder, or (2) working, the belt then being in contact with the cylinder, with a pressure determined by the force of the spring and the natural weight of the assembly, and an embraced are likewise being predetermined. Consequently, during the launching or start-up of thread advancement, and principally in the case of machines for texturizing by false twist, numerous breaks occur, due to tension jolts which are produced principally when the false twist spindle is started up, and by the difficulty of precisely synchronizing the action of the feeders placed above and below the spindle. 7

Now we have found, and this is the object of the present invention, a thread feeder which limits breaks to a minimum and facilitates start-up of the machine on which it is used. As was said, such a device is particularly adapted to machines for texturizing by false twist, but it could also be used in any other type of textile equipment and principallyin every case where tension jolts are produced on the thread when starting up.

The thread feeder according to the invention comprises a rotary cylinder and an endless belt which, in normal operation, is applied along an arc of a circle against the cylinder. The thread to be fed passes between the belt and the cylinder with the belt being mounted on two idler rollers attached to a support arm. Such device is characterized in that the support arm is associated with means for positioning and pretensioning the belt in an intermediate position between the idle and working positions. The belt, in this intermediate embraced arc and the pressure exerted by the belt is much less than those used in normal operation.

In practice the arc embraced by the belt on the driving cylinder during intermediate position is preferably at least five times less than the are in normal working position, and the force of application of the belt on the cylinder is less than that exerted in normal operation. In general, the arc is less than 0.3 radian and the force of application'less than I kilogram.

The means for positioning the belt with respect tothe driving cylinder are preferably constituted by an adjustable stop which rests on the driving cylinder during start-up and limits the displacement of the belt, and consequently, the arc embraced by the belt on the driving cylinder during the launching. As an option, instead of pressing directly on the driving cylinder the beltpositioning stop can rest on a second stop fixed in a position predetermined with respect. to the driving cylinder.

In one method of embodiment, the means for pretensioning the belt are constituted by a tension roller pressing on the belt during start-up, and ceasing its action in normal running. Preferably, the displacements of the means for pretensioning are synchronized with those of the means for positioning, and are, for example, directly controlled by the latter.

In a second method of embodiment, the means for pretensioning the belt are constituted by means for adjusting the separation of the idler rollers supporting the belt.

Moreover, these means for positioning and pretensioning the belt are all combined with means of return (springs), to idle position, synchronized with the displacementof the belt, when the latter is brought into its normal working position.

The invention will be better understood from the description which follows, and from the attached drawings which illustrate examples of embodiment and application of thread feeders according to the invention.

The drawings show, in lateral or side view, the respective positions and functions of the various members forming the feeder in the principal phases of its operation. FIGS. 1,2 and 3 illustrate a first example of embodiment, and FIGS. 4 and 5 illustrate a second example of embodiment.

FIG. 1 is a schematic side view of a feeder of the present invention in its idle position.

FIG. 2 is a schematic side view of the feeder in its intermediate position during the launching of the thread.

FIG. 3 is a schematic side view of the feeder at work, that is to say innorrnal operation.

FIGS. 4 and Sshow in schematic side view a second type of feeder accordingto the invention, in intermediate launching position (FIG. 4) and normal operation (FIG. 5).

For greater facility, there has been represented in these drawings only the principal components of the feeder, disregarding the housing and the supports in which these components are fixed.

EXAMPLE 1 As is seen in FIGS. 1, 2 and 3, the feeder has a driving cylinder 1 driven by suitable means, not shown, in con tinuous rotation about its longitudinal axis or shaft 2 which is fixed in space. An endless belt 3 is borne by two idler rollers 4 and 5 which are mounted freely rotatable on two shafts 6 and 7 whose axes are parallel to axis 2 of the driving cylinder. Shafts 6 and 7 are mounted on a supporting arm 8 which can pivot about an axis or shaft 9 fixed with respect to the driving cylinder 1. As stated, the endless belt 3 is designed to be applied overa part of the perimeter of cylinder 1 in order to insure, in combination with the latter, the driving engagement and advancement of the thread 10 (FIG. 2) passing between them.

Support arm 8 is subject to the action of a spring 11 or any other equivalent device. In the present case, the spring 11 acts in compression on the end of arm 8, and its point of application 12 is fixed with respect to pivoting axis 9. Spring 11 is positioned in such a way that, according to-the position of the feeder, (1) it keeps the assembly of belt 3 and rollers 4, 5 in open position with respect to the cylinder 1 when the feeder is idle (FIG. 1), (2) it participates in the maintenance of the assembly of belt 3 and rollers 4, 5 in a launching equilibrium position (FIG. 2), and (3) it insures the pressure of the belt on the cylinder 1 in normal operation (FIG. 3).

According to the invention, the supporting arm 8 is connected on the one hand, with means for positioning and pretensioning the belt when the latter is in launching position (FIG. 2) in contact along a small embraced are (A) and in light pressure with cylinder 1 and, on the other hand, is connected with means for return of the positioning and pretensioning means when the belt is brought into normal operating position (FIG. 3) in contact along an embraced arc (B) longer than are (A).

The means for positioning and pretensioning are formed principally, as follows. For the means for positioning, there is provided an adjustable stop means or member 13 mounted on a pivoting arm 14 which, during the launching (FIG. 2), presses on the driving cylinder and determines the position of the belt with respect to the cylinder. For the means for pretensioning, there is provided a roller 15 mounted on a pivoting arm 16 which during launching presses on the belt and determines the pressure exerted by the latter on the cylinder.

The position of stop member 13 and the pressure exerted by roller 15 are adjustable and will be a function of the thread to be handled or treated. In each case they will be adjusted in such a way as to advance the thread only if the tension of the latter is below its breaking limit.

According to the embodiment of FIGS. 1-3, the arms 14 and 16 pivot around an axis or shaft 17 which is fixed with respect to the pivoting axis 9 of support arm 8. Arm 14 is subject to the action of a spring 18 of adjustable force, whose point of application 19 is fixed with respect to axes 9 and 17 and is situated such that according to the orientation of arm 14 it will either insure the position of stop'member 13 during the launching, or repel or remove stop member 13 from its working position when the belt is put into normal operating position. Arm 16 is likewise subject to the action of a spring 20 whose point of application 19' is fixed with respect to axes 9 and 17 and is situated in such a way that according to the orientation of arm 16 it will either insure the pressure of roller 15 during the launching, or repel or remove the roller 15 from its working position when the belt is put into normal working position. Op-

tionally, arms 14 and 16 could be made to pivot around different fixed axes.

This device of FIGS. 1-3 works as follows. In idle position (FIG. 1 with belt 3 and driving cylinder 1 separated, tensioner roller 15 is brought in contact with belt 3. The pressure which it exerts on the belt 3, and which is a function of the pressure which we wish to impart during the launching, is determined by the action of spring 20 acting on arm 16 of roller 15, the stop member 13 being held by the action of spring 18 acting on arm 14. The assembly thus positioned is then brought into intermediate working position (FIG. 2) by simply pivoting arm 8 around axis 9. This position is obtained by the pressure of stop member 13 on cylinder 1. In this intermediate position, the belt embraces the driving cylinder only over an arc (A) of short length, and exerts on the latter a pressure determined principally by spring 20. This pressure must in no case permit the advancing of the thread if the tension of the latter in creases above the tensioner. In this way, during the launching, the belt does not drivingly advance the thread if the tension of the latter is greater than the traction force exerted by the belt. When the tension in the thread diminishes and stabilizes, the feeder again advances the thread, and the belt can then be put into normal position, in such a way that it will embrace cylinder 1 over an arc (B) at least five times longer than are (A) embraced during the launching. For this (FIG. 3), one presses on the assembly bearing the belt to move springs 18 and 20 into return position of arms 14 and 16 which repels or moves tensioner roller 15 and stop member 13 into idle position (position marked in dotted lines in FIG. 1). When a break occurs, or when the machine is shut down, it is sufficient to raise the belt and return the tensioner roller and stop member into position (solid lines in FIG. 1) in order to be able to produce a new launching.

EXAMPLE 2 This example is illustrated by FIGS. 4 and 5. Accordingly to this method of embodiment, the feeder has, as in Example 1, a driving cylinder 21 moved by suitable means, not shown, in continuous rotation about its longitudinal axis or shaft 22 which is fixed in space. An endless belt 23 is supported by two idler rollers 24, 25 mounted freely rotatable on axes or shafts 26, 27 parallel to the axis 22 of the driving cylinder 21.

The means for positioning belt 23 are constituted by a stop member 28 which presses on driving cylinder 21 during start-up (FIG. 4) and is mounted at the end of an arm 29 pivoting around an axis or shaft 30. The means for pretensioning the belt are constituted by a means for adjusting the interval (E) between the idler rollers 26, 27. This means for adjusting the interval is formed by an arm 31 pivoting about an axis or shaft 32, one end of which 33 is fixed to axis 27 of idler roller 25. The means for positioning the belt, and the means for pretensioning are combined together by means of a spring 34 which tensions the belt.23 during the launching and serves as a means for return to idle position of the positioning stop member 28 when belt 23 is brought into normal working position (FIG. 5). The position of arm 31 and consequently of roller 25 is determined by a stop element 35.

This device works as follows. During the launching (FIG. 4), stop 28 is in contact with driving cylinder 21. Spring 34 acts on arm 31 to move roller 25 away from roller 24 which stretches belt 23. Belt 23 is then in contact with cylinder 21 over only a small embraced arc (A). In order to bring the assembly into normal working position, it is sufficient to pivot arm 29 to disengage stop 28 from cylinder 21, which brings spring 34 into a position such that its action on arm 31 brings rollers 24 and 25 together. Belt 23 embraces cylinder 22 along an arc (B) larger than the launching are (A), and the spacing between rollers 24 and 25 is limited to a length determined by contact of arm 31 against stop element 35.

The devices according to the present invention have great advantages over those utilized heretofore and permit, among other things, launching or start-up, with out special precautions, of advancement of threads which it has been very difficult, even impossible, to work on modern machines for texturizing by false twist, owing to the breaks which occurred during start-up.

These devices can advantageously be used during the start-up of machines in which simultaneous drawing and texturizing are carried out.

That which is claimed is:

1. In a thread feeding device for textile machines including a rotary driving cylinder, an endless belt mounted for movement on idler rollers supportably attached to a pivotable supporting arm, and wherein the supporting arm is pivotably movable to locate the belt in an idle position out of contact with the driving cylinder and in a normal thread feeding position in contact with the driving cylinder along an arc of the surface thereof to advance thread passing between the belt and cylinder; the improvement therein comprising means for pretensioning and maintaining the belt in an intermediate position between said idle and said normal thread feeding positions to contact the belt with the driving cylinder over a smaller embraced arc and at a lower pressure than that employed to advance the thread when the belt is in said normal thread feeding position.

2. A thread feeding device according to claim 1 wherein the means for intermediately positioning and pretensioning the belt are combined with means for re turning the positioning and pretensioning means to an idleposition in synchronization with the displacement of the belt when the latter is brought into normal work ing position against the cylinder.

3. A thread feeding device according to. claim 1 wherein the means for intermediately positioning and pretensioning comprise an adjustable stop means which engages the driving cylinder during start-up to control the arc embraced by the belt on the cylinder and the pressure of the belt .on the cylinder.

4. A thread feeding device according to claim 1 wherein the means for intermediately positioning the belt comprise a stop means which presses on a fixed member adjustable with respect to the position of the driving cylinder.

5. A thread feeding device according to claim 1 wherein the means for pretensioning the belt comprise a positionable stretcher roller whose displacements are synchronized with those of the positioning means.

6. A thread feeding device according to claim 1 wherein the means for pretensioning the belt comprise means for adjusting the distance between the idler rollers which support the belt.

7. A thread feeding device according to claim 1 wherein the belt is positioned in intermediate position so that the arc embraced by the belt on the driving cylinder is at least five times smaller than that embraced when the belt is in normal working position and the force exerted by the belt on the cylinder in intermediate position is at maximum equal to that exerted in normal working position. I

8. In a thread feeding device for textile machines having a rotatable driving cylinder and an endless belt which in operating position engages the surface of the driving cylinder along an arc of a circle to be moved thereby and to advance a thread passing between the belt and cylinder, and wherein the belt is supported for movement on two idler rollers which are attached to a pivotable support arm so that the belt is positionable between an operating position engaging the driving cylinder to advance thread and an idle position out of contact with the driving cylinder; the improvement therewith comprising means for positioning and pretensioning the belt in an intermediate position of engagement with the driving cylinder between said idle position and said operating position, said means comprising stop means associated with the belt supporting means for limiting the amount of pivotal movement of the belt into engagement with the driving cylinder and movable means for tensioning the belt about the idler rollers while in said intermediate position of engagement with said driving cylinder.

9. A thread feeding device as. defined in claim 8 wherein said stop means comprise means for engaging the surface of the cylinder and means for positioning said engaging means into and out of contact with the surface of the cylinder.

10. A thread feeding device as defined in claim 8 wherein said movable means comprise roller means for engaging the belt to tension the same about the idler rollers.

11. A thread feeding device as defined in claim 8 wherein said movable means comprise means for varying the relative distance between the axes of the idler:

rollers to tension the belt thereabout. 

1. In a thread feeding device for textile machines including a rotary driving cylinder, an endless belt mounted for movement on idler rollers supportably attached to a pivotable supporting arm, and wherein the supporting arm is pivotably movable to locate the belt in an idle position out of contact with the driving cylinder and in a normal thread feeding position in contact with the driving cylinder along an arc of the surface thereof to advance thread passing between the belt and cylinder; the improvement therein comprising means for pretensioning and maintaining the belt in an intermediate position between said idle and said normal thread feeding positions to contact the belt with the driving cylinder over a smaller embraced arc and at a lower pressure than that employed to advance the thread when the belt is in said normal thread feeding position.
 2. A thread feeding device according to claim 1 wherein the means for intermediately positioning and pretensioning the belt are combined with means for returning the positioning and pretensioning means to an idle position in synchronization with the displacement of the belt when the latter is brought into normal working position against the cylinder.
 3. A thread feeding device according to claim 1 wherein the means for intermediately positioning and pretensioning comprise an adjustable stop means which engages the driving cylinder during start-up to control the arc embraced by the belt on the cylinder and the pressure of the belt on the cylinder.
 4. A thread feeding device according to claim 1 wherein the means for intermediately positioning the belt comprise a stop means which presses on a fixed member adjustable with respect to the position of the driving cylinder.
 5. A thread feeding device according to claim 1 wherein the means for pretensioning the belt comprise a positionable stretcher roller whose displacements are synchronized with those of the positioning means.
 6. A thread feeding device according to claim 1 wherein the means for pretensioning the belt comprise means for adjusting the distance between the idler rollers which support the belt.
 7. A thread feeding device according to claim 1 wherein the belt is positioned in intermediate position so that the arc embraced by the belt on the driving cylinder is at least five times smaller than that embraced when the belt is in normal working position and the force exerted by the belt on the cylinder in intermediate position is at maximum equal to that exerted in normal working position.
 8. In a thread feeding device for textile machines having a rotatable driving cylinder and an endless belt which in operating position engages the surface of the driving cylinder along an arc of a circle to be moved thereby and to advance a thread passing between the belt and cylinder, and wherein the belt is supported for movement on two idler rollers which are attached to a pivotable support arm so that the belt is positionable between an operating position engaging the driving cylinder to advance thread and an idle position out of contact with the driving cylinder; the improvement therewith comprising means for positioning and pretensioning the belt in an intermediate position of engagement with the driving cylinder between said idle position and said operating position, said means comprising stop means associated with the belt supporting means for limiting the amount of pivotal movement of the belt into engagement with the driving cylinder and movable means for tensioning the belt about the idler rollers while in said intermediate position of engagement with said driving cylinder.
 9. A thread feeding device as defined in claim 8 wherein said stop means comprise means for engaging the surface of the cylinder and means for positioning said engaging means into and out of contact with the surface of the cylinder.
 10. A thread feeding device as defined in claim 8 wherein said movable means comprise roller means fOr engaging the belt to tension the same about the idler rollers.
 11. A thread feeding device as defined in claim 8 wherein said movable means comprise means for varying the relative distance between the axes of the idler rollers to tension the belt thereabout. 